Thank you both, I got it! I put a screwdriver between the tensioner and belt and used it to leverage it on.
Unfortunately this job has been a multi month, casual ordeal. Now that I have the timing covers back on, I can't remember how to reinstall the vibration damper and crank pulley.
I'm thinking the vibration damper isn't going in far enough because the crank bolt won't catch thread unless I take the washer off, but it's difficult to get the damper on and off. Also the crank pulley is in two sections that seem to bolt to themselves but there isn't anything to thread into.
Tips on removing/installing the damper?
Did I lose some kind of mounting plate for the two halves of the crank pulley?
Are all these questions and more already answered somewhere and I didn't notice?
I'm a complete novice here, any help appreciated